Fix bug #15260 with building and installing Emacs in non-ASCII directories.

Fix bug #15260 with building and installing Emacs in non-ASCII directories.

 src/xdisp.c (message3_nolog, message_with_string): Encode the string
 before writing it to the terminal in a non-interactive session.
 src/lread.c (openp): If both FILENAME and SUFFIX are unibyte, make
 sure we concatenate them into a unibyte string.
 src/fileio.c (make_temp_name): Encode PREFIX, and decode the
 resulting temporary name before returning it to the caller.
 (Fexpand_file_name): If NAME is pure-ASCII and DEFAULT_DIRECTORY
 is a unibyte string, convert NAME to a unibyte string to ensure
 that the result is also a unibyte string.
 src/emacs.c (init_cmdargs): Use build_unibyte_string to make sure we
 create unibyte strings from default paths and directory/file
 names.
 src/coding.h (ENCODE_FILE): Do not attempt to encode a unibyte
 string.
 src/callproc.c (init_callproc): Use build_unibyte_string to make
 sure we create unibyte strings from default paths and
 directory/file names.
 src/buffer.c (init_buffer): Don't store default-directory of
 *scratch* in multibyte form.  The original problem which led to
 that is described in
 http://lists.gnu.org/archive/html/emacs-pretest-bug/2004-11/msg00532.html,
 but it was solved long ago.

 lisp/startup.el (normal-top-level): Move setting eol-mnemonic-unix,
 eol-mnemonic-mac, eol-mnemonic-dos, and also setup of the locale
 environment and decoding all of the default-directory's to here
 from command-line.
 (command-line): Decode also argv[0].
 lisp/loadup.el: Error out if default-directory is a multibyte string
 when we are dumping.
 lisp/Makefile.in (emacs): Don't set LC_ALL=C.

 leim/Makefile.in (RUN_EMACS): Don't set LC_ALL=C.

 configure.ac: Don't disallow builds in non-ASCII directories.